AB1421 IMPACT OF HOSPITALIZATION ON CLINICAL OUTCOMES IN PATIENTS WITH CONNECTIVE TISSUE DISEASE ASSOCIATED INTERSTITIAL LUNG DISEASE (CTD-ILD) - A SINGLE CENTER OBSERVATIONAL STUDY
Authors: N. Kaur, X. Xie, A. Korogodina, B. Ayesha, K. Cleven, A. Kumthekar
Journal: Annals of the Rheumatic Diseases (2022)

Background Interstitial lung disease(ILD) is major cause of morbidity and mortality in patients with connective tissue disease (CTD). Hospitalization is being increasingly recognized as poor prognostic indicator in these patients. Objectives The objective of our study was to assess the impact of hospitalization on clinical outcomes in patients with CTD-ILD. Methods We conducted a retrospective chart review of patients with radiologically or biopsy proven ILD associated with rheumatologist diagnosed CTD who were seen at Montefiore Medical Center between January 2007 and December 2018. Patients with age&gt;18 years who had either 2 CT scans of the chest and/or 2 sets of pulmonary function tests (PFT) atleast 6 months apart were included in the study. Clinical demographics, cause of hospitalization, length of stay, use of immunosuppression and mortality were identified. Patients were stratified into 2 cohorts; non-hospitalized and hospitalized patients. The latter cohort was further sub-stratified into patients with cardiopulmonary vs. non-cardiopulmonary hospitalization (Figure 1). Two-sample t-tests and Wilcoxon’s rank sum tests were used for comparing the continuous variables. Chi-square tests and Fisher’s exact tests were used for comparing the categorical variables as appropriate. Kaplan-Meier method was used for calculating the survival probabilities, and log-rank tests were used to compare differences between the groups. Results During the study period, we identified 213 patients with CTD-ILD using ICD 9/10 code. Of the 213 patients, 96 met our inclusion criteria and 73 (76%) had at least 1 hospitalization (Figure 1). Both groups were similar in baseline clinical characteristics but we identified significantly higher transplant referrals in the hospitalized group(23.9%) vs. non-hospitalized group(0%) (Table 1). Overall rheumatoid arthritis (29.2%) was the most common CTD associated ILD followed by inflammatory myositis (21.9%) and scleroderma (14.6%). Median time from diagnosis of ILD to first hospitalization was 1.42 years. Table 1. Baseline Characteristics of patients with CTD-ILD Characteristic Entire Cohort (n = 96 ) Patients with CTD-ILD and hospitalization (n = 73 ) Patients with CTD-ILD and no hospitalization (n = 23 ) p-value Age(mean ± SD) 54.15 ± 13.97 54.82 ± 13.77 52.00 ± 14.71 0.40 Female, n (%) 76 (79.2) 56 (76.7) 20 (87.0) 0.39 Race, % (n) 0.10 Black 38 (39.6) 31 (42.5) 7 (30.4) White 4 (4.2) 3 (4.1) 1 (4.4) Others 54 (56.2) 39(53.4) 15(65.3) Ethnicity, % (n) (Hispanic) 44 (53.7) 35 (53.0) 9 (56.3) 0.82 Former or active smoker, % (n) 41 (42.7) 34 (46.6) 7 (30.4) 0.17 Pulmonary hypertension, % (n) 28 (31.1) 24 (33.3) 4 (22.2) 0.36 FVC, n (%) 0.37 Moderately severe(47.1-64.2) 37 (44.6) 26 (40.6) 11 (57.9) Severe(24.3-47.0) 7 (8.4) 6 (9.4) 1 (5.3) DLCO, n(%) 0.30 Moderate 26(31.7) 23(37.1) 3(15.0) Severe 25(30.5) 17(27.4) 8(40.0) Immunosuppression, n(%) 78 (81.3) 59 (80.8) 19 (82.6) 1.00 Transplant referral, n(%) 17 (18.3) 17 (23.9) 0 (0) 0.01 The patients hospitalized for cardiopulmonary cause were significantly older(57.2 ±13.1 years) than those admitted with non-cardiopulmonary cause(49.2±14.8 years)(Mean±SD). Older age (HR 1.95, p=0.02) and length of stay greater than 7 days for cardiopulmonary cause(HR 4.82,p=0.01) was associated with higher risk of mortality. Kaplan Meier curve analysis showed that hospitalization (p-value=0.02) was associated with statistically significant increased risk of death. Conclusion -Hospitalization in CTD-ILD patients especially length of stay more than 7 days due to cardiopulmonary causes was associated with statistically significant increased risk of death. Male gender and older age was associated with a worse prognosis in patients who were hospitalized. References [1]Ratwani AP, Ahmad KI, Barnett SD, Nathan SD, Brown AW. Connective tissue disease-associated interstitial lung disease and outcomes after hospitalization: A cohort study. Respiratory Medicine. 2019;154:1-5. doi:10.1016/j.rmed.2019.05.020 Disclosure of Interests None declared